Apparatus for packaging articles between two continuous sheets



H. lrTOEWS Nov. 30, 1954 APPARATUS FOR PACKAGING ARTICLES BETWEEN TWO CONTINUOUS SHEETS Filed April 17, 1952 8 Sheets-Sheet 1 Nov. 30, 1954 H. l. TOEWS 2,595,483

APPARATUS FOR PACKAGING ARTICLES BETWEEN" TWO CONTINUOUS SHEETS Filed April 17, 1952 8 Sheets-Sheet 2 Nov. 30, 1954 H. I. TOEWS 2,695,483

APPARATUS FOR PACKAGING ARTICLES BETWEEN TWO CONTINUOUS SHEETS Filed April 17, lsz s Sheets-Sheet s a7 HA5 Arr-02mm:

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APPARATUS FOR PACKAGING ARTICLES BETWEEN "TWO CONTINUOUS-SHEETS Filed April 17, 1952 8 Sheets-Sheet 5 A85 /5/ l J 67' HIS ATT'a-eMErS Nov. 30, 1954 ugws 2,695,483

APPARATUS FOR PACKAGING ARTICLES BETWEEN TWO CONTINUOUS SHEETS Filed April 17, 1952 8 Sheets-Sheet 6 H. I. TOEWS Nov. 30, 1954 2,695,483

APPARATUS FOR PACKAGING ARTICLES BETWEEN TWO CONTINUOUS SHEETS 8 Sheets-Sheet 7 Filed April 17, 1952 xxukism fin 1979/6, fire/v Emmi/74805 H. l. TOEWS Nov. 30, 1954 APPARATUS FOR PACKAGING ARTICLES BETWEEN TWO CONTINUOUS SHEETS 8 Sheets-Sheet 8 Filed April 17, 1952 PRL-SSURE' JfMS/ 7/1/11 5 WI TCH APPARATUS FOR PACKAGING ARTICLES EETWEEN TWO CONTINUOUS SHEETS Harry I. Toews, Lynwood, Calif.

Application April 17, 1952, Serial N0. 282,748

21 Claims. (Cl. 53 -32) This invention relates to packaging machines, more particularly to packaging machines in which a unit that is to be enclosed is initially positioned between'two continuous sheets and the packaging operation comprises sealing the two sheets together around the unit and cutting the two sheets to release the sealed unit therefrom.

The general object of the invention is to provide a relatively compact apparatus of this character that operates in an ei'ficient automatic manner at a high production rate.

With reference to compactness as well as structural simplicity, a feature of the preferred practice of the invention is a combination of sealing and cutting means providing a central opening in the sealing meansfor the discharge of scaled units with the cutting means extending on at least two sides of the sealing means to cut the two sheets for release of the sealed units therefrom. Thus, a unit to be packaged or wrapped moves from an initial feed station to a wrapping station where a wrapping cycle is carried out and the final package simply drops through the sealing means out of the way. Such a short processing path makes it possible to embody the invention in a compact machine.

- A further feature of the preferred practice of the in-- vention is the use of a vertically reciprocating platform to receive the wrapped product that drops from the wrapping station. An object of the invention in this respect is to provide a simple eiiicient means to actuate and coordinate the sealing mechanism, the cutting mechanism and the receiving platform for smooth functioning of the movable parts and gentle handling of the product.

The preferred embodiment includes an inner ringshaped sealing means through which the finished product is released and an outer ringeshaped cutting means concentrically surrounding the sealing means. The receiving platform reciprocates between an upper receiving position immediately below the sealing ring and a lower discharge position. A further object is to provide simple means to discharge the finished product from the receivingtplatform and this object is accomplished simply by providing automatic means to tilt the platform in the course of its downward movement. The product slides in an easy-going manner from the platform to a suitable discharge chute.

A feature of the invention is the manner in which this cycle of sealing, cutting. and discharging operations is carried out by a simple cyclic-actuating mechanism using a simple cam arrangement for coordination of the sequential steps in the cycle.

Another preferred object of the invention is to interlock the conveying mechanism functionally with the sealing, cutting and dischargingcycle to providean efficient over-- all cycle that is closely timed for high production. In this regard, a feature of the invention is the concept of making the over-all cycle responsive to movement of a unit into the wrapping station. of cessation of conveyor operation and initiation of the sealing and cutting cycle.

A further object of the invention is tomake the overall cycle additionally responsive to the presence of units at the feeding station. The apparatus will operate automatically at a high rate as long as units are introduced at the feed station but will stop automatically in the absence of a new unit. Thus, with a new unit at the feed station and with no unit at the wrapping station, the conveyor will advance to bring a new unit to the wrapping station. As previously eXplained,qthe arrival of a The response consists new unit stops the conveyor and starts the sealing and cutting cycle.

While the invention is .widely applicable, it has been initially embodied in an apparatus for packaging tortillas, which are pancake-shaped cooked food products that must be handled with a certain amount of care. This particular practice of the invention will be described herein for the purpose of disclosure as well as to provide adequate guidance for those skilled'in the art who may have occasion to apply the same principles to other specific packaging problems.

The various objects and advantages of the invention will be readily understood from the detailed description taken with the accompanying drawings.

in the drawings, which are to be regarded as merely illustrative,

Fig. 1 is a perspective view of an initial embodiment of the invention;

Fig. 2 is a perspective view of the final packaged product with parts broken away to show the structure of the package;

Fig. 3 is a side elevation of the apparatus with portions of walls broken away to reveal concealed structure:

Fig. 4 is a fragmentary plan view of the top of the apparatus at the feed station, the view being in the region indicated by the line 44 in Fig. 3;

Fig. 5 is an enlarged sectional view taken as indicated by the line 55 of Fig. 4;

Fig. 6 is a transverse section of the apparatus taken as indicated by the lines 66 of Figs. 3 and 8;

Fig. 7 is a fragmentary section along the line 7-7 of Fig. 8 showing an air valve for controlling the receiving platform;

'Fig. 8 is a plan view of the major portion of the apparatus;

Fig. 9 is an enlarged section taken as indicated by the line 99 of Fig. 8 showing a cam-actuated switch;

Fig. 10 is a longitudinal section taken as indicated by the broken line 10-10 of Fig. 8;

Fig. 11 is an enlarged fragmentof Fig. 10;

Fig. 12 is an enlarged section taken on the line 1212 of Fig. 8 showing the construction of the sealing and cutting mechanism;

Fig. 13 is a horizontal section taken on the lines 1313 of Figs. 6 and 12;

Fig. 14 is a similar section looking upward, the section being taken on the line 141*4of Fig. 12;

Fig. 15 is a horizontal section taken on the line 15- 15 of Fig. 12 showing the lower sealing means and lower cutting means in plan;

Fig. 16 is a horizontal section taken as indicated by the line 1616 of Fig. 12, showing the upper sealing means and upper cutting means as seen from below;

Fig; 17 is an enlarged fragmentary section taken as indicated by the line 17-17 of Fig. 15;

Fig. 18 is a schematic view, incorporating a wiring diagram and illustrating how the over-all cycle of the apparatus is controlled;

Fig. 19 is a perspective view of a second embodiment of the apparatus with parts broken away for clarity; and

Fig. 20 is a transverse section through the sealing and cutting means of the apparatus shown in Fig. 19.

General description erence to Figs. 1, 3 and 6.

The apparatus frame generally designated by the numeral supports a conveyor table 31 that extends from what may betermed a feed station, generally designated 32, to what may be termed a wrapping station, generally designated 33, inside a housing 34 at the rear of the apparatus. The housing 34 is mounted on the frame 30 and is provided with an overhead door 35. The overhead door 35 in its closed position shown in Fig. 1 provides liberal clearance above the conveyor table 31.

A bracket 39 at the front end of the machine journals a shaft 40 supporting a supply roll 41 to supply a lower wrapping sheet 42. The wrapping sheet 42 is drawn from the supply roll over a guide. bar 43 andthen along the conveyor table 31 toward theend of the apparatus in the housing 34. The tortillas, which have the form of thin pancakes, are deposited on the lower wrapping sheet 42 at the feed station 32 in groups or stacks 46 which are the units to be packaged. Since it is essential that the stacks 46 be positioned on the lower sheet 42 in accurate in alignment with the wrapping station, a suitable guide bar 47 overhangs the sheet, the guide bar being supported by a pair of suitable angular brackets 48.

Inside the housing 34 a supply roll 50 is rotatably supported'by a suitable pair of brackets 51 and is frictionally engaged by an arcuate pressure plate 52 that resists rotation of the roll and thereby places tension on an upper wrapping sheet 53 as it is drawn from the roll. The upper wrapping sheet 53 passes under a guide bar 54 in front of the wrapping station and over a second guide bar 55 beyond the wrapping station. Both the lower wrapping sheet 42 and the upper wrapping sheet 53 pass between a lower driven roller 56 and a co-operating upper pressure roller 57 which serve to draw the two sheets through the apparatus.

At the wrapping station 33 each successive stack 46 stopsin register with means which first seals the upper and lower wrapping sheets 42 and 53 together around the periphery of the stack and then cuts the two sheets to free the sealed stack. The sealing and cutting means are ring-shaped to permit the final package to drop therethrough onto a receiving platform generally designated 69. The receiving platform 60 thereupon moves vertically downward and tips or tilts to slide the finished package onto a discharge chute 61 that extends laterally out of the housing 34.

Mechanism to drive the two sheets The lower wrapping sheet 42 passes between two wheels 65 and 66 on each side of the machine, the two wheels'co-operating to engage the margin of the sheet. The lower wheels 66 are mounted on short shafts 67 (Fig. 8) and the upper wheels 65 are journalled on bell cranks 68 (Fig. 3) which bell cranks are urged by suitable springs 69 in a direction to cause the upper wheel 65 to press the wrapping sheet against the corresponding lower wheel 66.

At least one of the short shafts 67 carrying the lower wheels 66 is provided with a sprocket 70 engaged by a continuous drive chain 71. The drive chain 71 is actuated by a second sprocket 72 on a shaft 73 that carries the previously mentioned driven roller 56. As best shown in Fig. 8, the shaft 73 is journalled in suitable bearings 75 and is actuated by an electrically controlled clutch 76. The clutch 76 is energized and controlled by the cable 77 through the medium of a pair of brushes 78 in contact with a corresponding pair of slip rings 79. When energized, the remotely controlled clutch 76 operatively connects the shaft 73 with a short drive shaft 80 in coaxial alignment therewith.

The drive shaft 80 extends laterally from a gear box 84 that houses suitable reduction gearing driven by a sheave 85. The sheave 85 is operatively connected to a second sheave 87 by a belt 88 and, as shown in Fig. 6, the second sheave 87 is driven in turn by a motor 90 mounted in the under portion of the apparatus.

As best shown in Fig. 8, the upper pressure roller 57 that co-operates with the lower driven roller 56 is carried by a shaft 91 mounted at its opposite ends in suitable bearings 92. The bearings 92 incorporate coiled springs 93 (Fig. 3) that act on the shaft 91 to press the upper roller downward, thereby to cause both of the wrapping sheets 42 and 53 to be drawn together through the apparatus.

Sealing and cutting mechanism As may be seen in Figs. 3, 6 and 15, the frame structure of the apparatus includes an upright box-like subframe at the wrapping station 33 comprising four vertical angle members 94 interconnected by various horizontal angle members 95. This subframe is mounted on two transverse channel members 96 (Fig. 6) of the main frame. The purpose of this subframe is to serve as means for mounting the sealing mechanism and the cutting mechanism at the wrapping station 33.

These mechanisms comprise essentially four ringshaped means, namely, an upper sealing means 98, a lower sealing means 99 co-operative therewith, an upper cutting means 100, and a lower cutting means 101 cooperative with the upper cutting means. It will be noted that the two cutting means 100 and 101 surrund the two 4 corresponding sealing means or at least lie on opposite sides of the two sealing means.

It is contemplated that in the operation to be performed at the wrapping station 33 the two sealing means 98 and 99 will move together first to seal the two sheets 42 and 53 together and then the two cutting means 100 and 101 will move together to cut the two sheets to release the sealed product for gravitation downward through the opening formed by the lower sealing means 99. It is further contemplated that the sheets 42 and 53 in the preferred practice of the invention will be made of a suitable thermoplastic material that may be sealed by'the simple application of pressure and heat. It will be apparent to those skilled in the art that various sheet materials may be employed such as cellulose acetate, rubber hydrochloride and vinyl chloride. It will be apparent that various mechanical arrangements may be utilized to bring the two sealing means and the two cutting means together in the desired manner and desired sequence.

In the construction of the first form of the invention shown in the drawings, the upper sealing means 98 and the upper cutting means 100 are both carried by a reciprocative support 104 in the form of a heavy circular plate. The upper sealing means 98 is a downwardly extending circular flange integral with the plate and the upper cutting means 100 is in the form of a relatively hard ring of rubber or other suitable material surrounding the circular flange. As best shown in Figs. 12 and 16, the reciprocative support 104 has two diametrically opposite ears 105 that are apertured to receive and embrace corresponding vertical guide rods 106. The two guide rods 106 are securely anchored in the ears 105, as by means of set screws 107, and extend slidingly into corresponding lower guide blocks 108. As shown in Fig. 15, the two guide blocks 108 are apertured for slidingly embracing the guide rods 106 in a snug manner and are mounted on the subframe by suitable screws 109. The upper ends of the two guide rods slidingly extend in like manner into upper apertured guide blocks 110 (Fig. 6). Thus, the reciprocative support 104 carrying the upper sealing means and upper cutting means is accurately guided in a vertical path of movement.

Preferably, suitable means is provided to guide and maintain the upper wrapping sheet 53 in the plane of the upper sealing and cutting means as they move downward against the portion of the upper sheet that is stretched between the two transverse guide rods 54 and 55. As may be seen in Fig. 3, theelevation of these two rods is slightly above the plane of the upper sealing and cutting means when the reciprocative support 104 is at its upper limit position. The sheet 53 is under appreciable tension because of the action of the pressure plate 52 in frict1onal engagement with the supply roll 50. The desired guiding means for contact with the upper surface of the sheet 53 may be in the form of a pair of angular sheet metal plates 114, best shown in Figs. 12 and 15, the two plates being suitably supported respectively by the two ears 105 on opposite sides of the reciprocative support 104.

As best shown in Fig. 17 the lower sealing means 99 is provided with a metal pressure shoe and is heated by an internal heating coil 116 that is energized by a pair of insulated metal conductors 117 connected to corresponding wires118. The lower sealing means 99 is fixedly mounted on an inner support cylinder 120 which, in turn, is mounted on the frame structure by four radial supporting lugs 121 as best shown in Figs. 12 and 15. The four lugs 121 are anchored to horizontal frame members 95 by suitable bolts 122.

Preferably, suitable guide means similar to the previously described upper guide plates 114 are provided to maintain the lower wrapping sheet 42 approximately in the fixed plane defined by the upper surface of the lower sealing means 99. For this purpose a sheet metal guide plate 125 with a large central opening may be mounted on the frame structure of the lower sealing means as best shown in Figs. 12 and 15.

The lower cutting means 101 is in the form of a sharp cylindrical blade that is removably mounted in an outer s PPOrt cylinder 126 by set screws 127. The outer support cylinder 126 is mounted on a horizontal support plate 128 having a circular opening 130 therethrough. It may be noted that the circular opening 130 is in line with the inner support cylinder 120 to erm a ontinuo s downwardly extending passag for the disc arge of the finish p o uct.

It i cont mplat d tha he s ppo Plate .128 will be free for vertical reciprocative movement forreciprocatingac ua icn f the t ing lade 101 and will b suitably guided in such vertical movement. To Provide free dom for such movement, the outer support cylinder 126 is provided with liberal vertical slots 134 (Fig. 12) to clear the fixed radial lugs 121 that support the inner cylinder 120. The desired vertical guidance may be provided by four vertical guide posts 135 having reduced .upper ends 136 that slidingly extend into corresponding bores 137 (Fig. 14) in the support plate 128.

The four guide posts 135 are fixedly mounted in a base plate 138 that is similar to the support plate 128 and, in similar manner, has a circular opening 139 to continue the passage for downward discharge of the finished product. It is contemplated that the base plate 138 will be adjustable and for this purpose it is moun by small screws 140 (Fig. 12) on the upper ends of four cap screws 144. The cap screws 144 are threaded into nuts 145 that are fixedly mounted on the channel members 96. Temporary loosening of the small screws 140 perrlits rotary adjustment of the cap screws 144 when desire Any suitable means may be provided to" reciprocate the support plate 128 vertically for moving the lower cutting means 101 to and from contact with the upper cutting means 100. Such contact is to occur when the upper cutting means 100 is at the lower limit position of the reciprocative support 104 on which it is mounted.

In the construction shown, four wheels 150 are mounted in suitable brackets 151 on the under side of the support plate 128 for co-operation with four corresponding cam members 152. The cam members 152 are unitary with two spaced slide bars 153 that slidingly rest on the base plate 138 and are slidingly held in position by suitable bolts 154. The bolts 154 which are mounted in fixed blocks 155 extend through suitable slots 156 in the slide bars. Preferably, suitable yielding means is provided to urge both slide bars 153 to positions retracting the cam members 152 from the wheels 150, such position being shown in Fig. 6. For this purpose, suitable helical springs 157 (Fig. 13) are connected to the bolts 154 atone end and are connected to the slide bars 153 at their other ends by suitable screws .160. As best shown in Fig. 12, each of the slide bars 153 is provided at its outer end with a roller 161 that serves as a follower to co-operate with a cam 162 on a camshaft .163.

It is apparent that the two springs 157 will urge the two slide bars 153 to the right as viewed in Fig. 12 to maintain continuous contact between the rollers 161 and the corresponding cams 162. When rotation of the cams 162 force the two slide bars 153 from the retracted position shown in Fig, 6 to the effective position shown in Fig- 12. the f r m mem r 152 on the slid bar move under the wheels 150 to raise the support plate 128 on the four guide posts 135. With continued rotation .of the camshaft 163 the slide bars 153 are permitted to return under the force exerted by the two springs.

Means to actuate sealing and cutting mechanism For the purpose of actuating the sealing and cutting mechanism, a sprocket wheel 168 on the previously mentioned drive shaft 80 (Fig. 8) is operatively connected by a chain belt 169 wih a sprocket wheel 170 that is rotatably mounted on a countershaft 171. The countershaft 171 is mounted in a pair of bearings 172. The sprocket wheel 170 rotates continuously on the counter-shaft 171 and is operatively connected with the countershaft by a suitable clutch 173 whenever it is desirable to operate the sealing and cutting mechanism through a sealing and cutting cycle.

In the construction shown, the clutch 173 is a singlerevolution electric clutch, the construction .of which is well known in the art. As best shown in Figs. and 11, the clutch 173 includes an inner collar 177 keyed to the countershaft 171 and an outer eccentric collar 178 forming a shoulder 179 the outer collar being rotatively mounted on the shaft 171. In the normal idle position of t e ounter h f 171 he outer eccentric c llar 17 is rotatably displaced relatively to the innereollar 177 by abutment of the shoulder 179 against a control plunger 180. Whenever the control plunger 180 is momentarily withdrawn from engagem nt with the shou er 7 .a suit ble pr ng 18 inter onn cting th e cen ri collar 178 and the inner oll r .177 rotates the ec en ric colla clockwise as viewed in ;Figs. 10 nd 11 and thereby causes the clutch 173 to interconnect the sprocket Wheel and the countershaft 171 to cause rotation of the countershaft. At the completion of a single revolution of the countershaft the shoulder 1179 of the eccentric collar again engages the control plunger and causes the eccentric collar to be displaced relative to the inner collar to restore the parts to their normal position and thereby disconnect the countershaft 171 from the sprocket wheel 170. Thus momentary withdrawal of the control plunger 180 causes one revolution of the counter.- shaft 171 to carry out one complete cycle of the sealing and cutting mechanism.

As best shown in Fig. 10, the plunger 180, which is slidingly mounted in a fixed sleeve 184; is continuously urged downward for engagement with the shoulder 179 by a suitable helical spring 185 in compression between the sleeve 184 and a flange 186 on the plunger. The upper end of hte plunger 180 is pivotally connected to an operating lever 187 that is fulcrumed at one end and has its opposite end connected to the core 189 of a suitable solenoid 190. Momentary energization of the solenoid 190 causes the plunger 180 to be lifted long enough to permit the shoulder 179 of the eccentric to escape for one revolution of the clutch 173.

The previously mentioned camshaft 163, which is journnalled in four suitable bearings 193, is actuated by the countershaft 171 through a pair of bevel gears 194. In addition to the previously mentioned two cams 162 for actuating the slide bars 153, the camshaft 163 carries an eccentric (Fig. 6) which is embraced by a split collar 196 on "the lower end of a connecting rod 197. The upper end of the connecting rod 197 operates a lever 200 that is centrally fulcrumed in a bracket 201 and is operatively connected to the previously mentioned reciprocative support 104 that carries the upper sealing and cutting means. In the particular construction shown, the lever 200 is connected to the reciprocative support 104 through a turnbuckle 202 of well-known construction which may be adjustably varied in length to shift the range of reciprocation of the support 104.

It is apparent that one complete rotation of the camshaft 163 in response to momentary energization of the clutch solenoid 190 will turn both cams 162 and the eccentric 195 through one complete revolution. The two cams 162 acting through the slide bars 153 cause 're ciprocation of the lower cutting means 101. as heretofore described and the eccentric 195 causes properly timed operation of the reciprocative support 104 car-rying the upper sealing and cutting means.

Discharge mechanism As heretofore stated, the packaged product released by the sealing and cutting means drops through the inner support cylinder 120 onto the receiving platform 60. .As shown in Figs. 12 and 14, the receiving. platform 60 is in the form of a metal plate having a pair of ears 206 on its under side by means of which it is pivotally mounted on the upper end of a vertical piston rod 207. The upper end'of the piston rod 207 carries a metal block 208 in which a pair of trunnion pins 209 are mounted and are secured by set screws 210. The cars 206 pivotally engage the two trunnion pins 209 to rnit the platform to swing between a normal horizontal position shown in full lines in Fig. 6 and a tilted position shown in dotted lines.

Normally a suitable helical spring 213 extending from the under side of the receiving platform .60 to a lower radial arm 214 on the piston rod yieldingly holds the platform against a stop shoulder 215 that is integral with the metal block 208. When the piston rod 207 moves downward, the reeciving platform 60 encounters a pair of spaced rods or posts 216 that are fixedly mounted in upright position on a fixed plate 217. Continued downward movement of the receiving platform causes the two fixed rods 216 to tilt the platform against the resistance of the springs 213, as shown in Fig. 6, thereby inclining the platform sufficiently to cause a wrapped product thereon to slide onto the previously mentioned discharge chute 61. o

Th pis on r 2 7 extends into an up ght air cylinder 220 that is anchored to the fixed plate 217 at its upper end. The piston rod 207 is connected to a piston (not shown) in the air cylinder 220 and suitable air lines are connected to opposite ends of the cylinder 220 to cause reciprocation of the piston rod 207 in proper synchronization' with the operation of the previously described sealing and cutting mechanism. Preferably, the required synchronization is accomplished by a three-way a1r valve 221, which, as best shown in Fig. 7, is controlled by a cam 222 on the previously mentioned camshaft 163. The three-way valve 221 which is connected to the opposite'ends of the air cylinder 220 by two alr l1n es 223 is connected to a suitable source of compressed arr by a supply line 224 and has a suitable air release port (not shown). The three-way valve 221 has an operating plunger 225 which presses outward against the cam222. At the normal position of the cam 222 shownm Fig. 7, the receiving platform 60 is in the upper limit position shown in Fig. 12. One complete revolution of the eccentric cam 222 causes the piston rod 207 'to retract downward in a suitably gradual manner to lower the receiving platform 60 to its lower tilted position and then at the end of the revolution of the cam theplunger 225 is released by the cam to its starting, positron to cause return of the receiving platform to its starting upper limit position.

Control of the over-all cycle While various control arrangements may be devised for various practices of the invention, the preferred control arrangement includes suitable switch means at the feed station 32 to operate in response to the presence of units of the product on the lower wrapping sheet 42. Such a switch means generally designated by numeral 230 in Figs. 3, 4 and 5 may include a lever 231 centrally fulcrumed on a pin 232 in a longitudinal opening 233 in the conveyor table 31 at the feed station 32. The lever 231 is biased by a suitable leaf spring 234 to seek a tilted position indicated by dotted lines in Fig. 5, at which tilted position the end of the lever toward the front of the machine is swung slightly below the level of the conveyor table and the other end of the lever directed toward the rear of the machine protrudes above the level of the conveyor table. Mounted on the under side of the lever 231 is an operating finger 235 which is in contact with-the operating plunger 236 of a pressure-sensitive switch 237. In the normal position shown in Flg. 5, the pressure-sensitive switch 237 is open but when the weight of a unit of the product on the rear end of the lever 231 rotates the lever into the plane of the conveyor table, the operating finger 235 depresses the operating plunger 236 to close the pressure-sensitive switch.

It is contemplated that the switch lever 231 will be so dimensioned and positioned, and units of the product to be wrapped will be so spaced on the travelling sheet 42, as to keep the pressure-sensitive switch 237 closed continuously so long as the travelling sheet 42 is supplied with the product at regular intervals at the feed station 32. Thus Fig. 4 shows in broken circles the positions of two successive stacks 46 of tortillas on the travelling sheet 42. The leading stack is for the moment holding down the rear end of the switch lever 231 but the next succeeding stack will advance to a position over the front end of the lever before the leading stack moves clear from the lever.

In addition to the switch means 230, the over-all control arrangement includes a second switch means that responds to the presence of the product at the wrapping station 33. The desired responsiveness to the presence of a unit at the wrapping station is provided in the preferred practice of the invention by a photoelectric control means 240 (Fig. 6) which is operatively sensitive to a beam of light from a lamp 242. It is contemplated that the arrival of a unit of the product at the wrapping station 33 will break the light beam and thereby open a switch in series with the previously mentioned pressure switch 237.

Instead of arranging for the breaking of the light beam to bring about this second switch action in direct manner, I prefer to have the breaking of the light beam initiate the cycle of operation of the sealing and cutting mechanism and to have the second switch action result from initiation of this cycle. Thus, the photoelectric control 240 responds to the breaking of the light beam by actuating the single revolution clutch 173 and the resulting rotation of the countershaft 171 mechanically opens a suitable switch 245 (Figs. 8 and 9) that is in series with.the previously mentioned pressure-sensitive switch 137. Thus, the switch 245 is indirectly responsive to the arrival of a unit of the product at the wrapping station 33.

The switch 245 has a control plunger 246 which is actuated by a suitable cam 247 on the countershaft 171,

the rotary position of the cam being such that the normally closed switch is opened by the cam in response to initial rotation of the countershaft 171. Since the switch 245 is depended upon to stop the movement of the lowerwrapping sheet 42 with the unit thereon correctly positioned at the wrapping station 33, there is a slight pre determined delay between the breaking of the light beam and the resulting opening of the switch 245. To compensate for this delay, the light beamis positioned to be cut by a travelling unit slightly before the travelling unit mally closed to make the solenoid-responsive photoelectrie control 240 operative but is opened by the cam 251, the cam automatically closing the switch again at the end of the sealing and cutting cycle. v

In the wiring diagram of the control arrangement shown in Fig. 18, a pair of leads 255 and 256 controlled by a master switch 257 are connected to a suitable source of current to energize the motor 90, the photoelectric control 240, and the lamp 242. The following circuit places the electric clutch 76 for moving the two wrapping sheets under the control of the pressure-sensitive switch 237 that responds to units of the product at the feed station as Well as under control of the switch 245' that responds to the arrival of a unit of the product at the wrapping station: wire 258 from lead 256 to one side of the pressure-sensitive switch 237, wire 259 from the other side of the pressure-sensitive switch to one side of the switch 245, wire 260 from the other side of the switch 245 to one side of the clutch 76 and wire 261 from the second side of the clutch to the lead 255. The photoelectric control means 240 in series with the switch 250 controls the single revolution clutch 173 through the following circuit: wire 264 from one side of the photoelectric control to one side of the clutch solenoid 190, wire 265 from the second side of the solenoid to one side of the switch 250 and wire 266 from the second side of the switch 250 to the second side of the photoelectric control.

It is apparent that as long as new units of the product are supplled to the feed station 32 to keep the pressuresensitive switch 237 closed, the operation of the electric clutch 76 to draw the lower wrapping sheet 42 and product units thereon from the feed station to the wrapping statlon will be governed by the operation of the switch 245 and the switch 250, in effect, responds to the arrival of units of theproduct at the wrapping station. The beam of llght from the lamp 242 is represented by the dotted line 267 m Fig. 18. When an advancing unit of the product carried by the lower wrapping sheet 42 cuts the light beam 267, the photoelectric control 240 responds by energizing the solenoid 190 to lift the plunger for causing the single-revolution clutch to operate. The resulting operation of the sealing and cutting mechanism causes the cam-actuated switch 250 to de-energize the solenoid until the end of the sealing and cutting, cycle. The initiation of the sealing and cutting cycle also causes the cam-actuated switch 245 to open and thereby brlng the travelling wrapping sheet 42 to a stop with the unit to be wrapped positioned properly in register with the wrapping station 33.

In the course of the sealing and wrapping cycle, the reclprocatlve support 104 first moves downward to bring the upper sealing means 98 against the lower sealing means 99, thereby to seal the two wrapping sheets to-. gether around the unit of the product at the wrapping station. Immediately afterwards, the lower cutting means 101 moves upward against the upper cutting means 100 to sever the sealed product from the two-wrapping sheets. The lower cutting means 101 then retracts downward and the reciprocative support 104 moves up ward to release the sealed product which then gravitates downward through-the inner-support cylinder 120 to ijcome at rest on the receiving platform 60. Y

' At this point in the over-all cycle, the discharge of the sealed unit from the wrapping station has restored the light beam 267 and since the sealing and cutting cycle has been completed, the cam switch 245 is closed to cause the electric clutch 76 to resume movement of the two sheets, it being assumed that there is a unit of the product at the feed station to keep the pressure-responsive switch 237 closed. The arrival of a new unit of the product at the wrapping station again causes initiation of the sealing and cutting cycle and again brings the travelling sheet to a stop. As the sealing and cutting cycle progresses, the cam 222 on the camshaft 163 actuates the air valve 221 to cause the receiving platform 60 to carry the previously wrapped unit downward and to slide the finished unit into ,the discharge chute 61. The receiving platform then returns to its upper position in time to receive the next wrapped unit.

Second form of the invention, Figs. 19 and 20 The second embodiment of the invention shown in Fig. 19 is similar in most respects to the first-described embodiment as indicated by the use of corresponding primed numerals to indicateicorresponding parts. The modifications are primarily in the means for actuating and performing the S al ng and cutting cycle.

The countershaft and the associated camshaft for carrying out the sealing and cutting cycle of the "first form of the invention are replaced by a single overhead countershaft 270 whichis journalled in suitable bearings 271. Rotatably mounted on the ,countershaft 270 is a suitable sheave 272 continuously driven by a belt 273 ,and a single-revolution clutch 274 under the control of a solenoid 275 is provided -to operatively interconnect the countershaft and sheave to causea complete rotation of the shaft whenever a unit of the product arrives at .the wrapping station.

The overhead countershaft 270 carries two cams 278 and 279 which actuate two switches 280 and 281, respectively, corresponding to the two previously described switches 245 and 250. The countershaft also carries a cam 282 to actuate an air valve 283 for controlling the receiving platform under the wrapping station as heretofore described.

In this second form of the invention, all of the moving parts of the sealing and wrapping mechanism are carried by a single reciprocative support 287 which is in the form'of a heavy metal disc having diametrically positioned guide arms 288. These guide arms are slidingly guided for vertical movement by pairs of guide rails 289 on each side of the apparatus.

The reciprocative support 287 is actuated by an eccentric 290 on the overhead .countershaft 270, the eccentric being embraced by a split collar 291 onthe upper end of an operating rod 292. .For adjustment in length the operating rod 292 extends into a sleeve 293 which is, turn, pivotally connected to a pair of ears 294 on the upper "side of a reciprocative support 287. Adjustment is accomplished by threaded engagement between the operating rod 292 and a suitable nut 295 that is fixedly mounted on the upper end of the sleeve 293.

The reciprocative support 287 carries an upper cutting means in the form of an outer cutting ring or circular I knife 300 and carries an upper sealing means 301 in the form of a ring member having a heating element 302 incorporated therein. The upper sealing means 301 is mounted on the reciprocative support 287 by suitable helical springs 303. Preferably, the reciprocative support 287 is also provided with an ejector plate 307 which is carried by headed pins 308' extending loosely upward through the reciprocative support. Suitable light helical springs 309 embrace the headed pins 308 to press the ejector plate 307 lightly downward.

Mounted below the level of the surface of the conveyor table at the wrapping station is a heavy fixed support plate 315 having a central circular opening 316 to permit the finished product to drop therethrough onto the receiving platform helow. Mounted on the fixed support plate 315 around the rim of the opening 316 isa lower sealing means 317 in. the form of a rigid metal ring, the ring being attached to the support plate by suitable screws 318. Surrounding the lower sealing means 3 s a ever c tting meaastfiw in th o m of I 10 .a suitable ring member supported by a ring-shaped rubber pad 320.

This second form of the invention operates in substantially the same manner and with the same over-all control cycle as the first form of the invention. When the reciprocative support 287 is moved downward by the eccentric 290, first, the heating ring or upper sealing means 301 contacts the lower sealing means 317 under pressure from the springs 303 to seal the-two wrapping sheets together around the margins of the unit of the product at the wrapping station. Immediately thereafter, the upper cutting means 300 moves against the lower cutting means 319 to sever the sealed product from the two wrapping sheets. In the meantime, the ejector plate 307 moves against the sealed product and applies downward pressure by virtue of the springs 309. Initial return movement upward of the reciprocative support 287 first separates the two cutting means and then eases pressure between the two sealing means to release the finished package. The light downward pressure of the ejector plate 307 assists the movement of the finished package downward through the fixed support plate 315 onto the receiving platform.

My description in detail of these preferred forms of the invention will suggest to those skilled in the art various changes, substitutions and other departures from my disclosure that fall within the spirit and scope of the appended claims.

I claim as my invention:

1. In an apparatus of the character described for packaging units of a product, the combination of: means to move a lower continuous wrapping sheet across a feed station to a wrapping station and to move an upper continuous sheet to the wrapping station above the lower sheet; a lower sealing means below the level of the lower sheet at said wrapping station, said sealing means having a central opening for downward passage of a sealed unit therethrough; sealing means above the level of said upper sheet at said wrapping station co-operative with said lower sealing means to seal the two sheets together around the unit; means at said sealing station to cut the two sheets to release the sealed units; and means to operate said sealing and cutting means in sequence to release a sealed unit to fall through said opening.

2. A combination as set forth in claim 1 which includes ejection means to force a sealed unit through said opening.

3. A combination as set forth in claim 1 which includes a receiver for the released sealed units, said receiver having an elevated position below said sealing means and cutting means; means to lower said receiver when a sealed unit is deposited thereon; and means to tilt the lowered receiver for gravitational discharge of the sealed units therefrom.

4. A combination as set forth in claim I in which said cutting means surrounds said sealing means.

5. In an apparatus of the character described for packaging units of a product, the combination of: means to move a lower continuous sheet across a feed station to a wrapping station and to move'an upper continuous sheet to the wrapping station above the lower sheet; a lower sealing means below the level of the lower sheet at said wrapping station, said sealing means having a central opening for downward passage of a sealed unit therethrough; and upper sealing means above the level of said upper sheet at said wrapping station co-operative with said lower sealing means to seal the two sheets together around a unit; means at said wrapping station to cut the two sheets to release the sealed units therefrom; a receiver for the released sealed units movable from an upper position to receive sealed units from said opening to a lower discharge position; means to displace sealed units from said receiver at its lower discharge position; and a mechanism operative in'a cycle to actuate said sealing means, cutting means and discharge means, said mechanism being responsive to movement of a unit into said wrapping station. a

6. In an apparatus of the character described for packaging units of a product, the combination of: means to move a lower continuous wrapping sheet across a feed station to a wrapping'sta'tion and to move an upper continuous wrapping sheet to the wrapping station above the lower sheet; upper and lower co-operating sealing means respectively above and below said two sheets at said wrapping station, said lower sealing means having a central opening for downward passage of sealing units therethrough; upper and lower co-operating cutting means respectively above and below said two sheets at said wrapping station, said cutting means extending on opposite sides of said sealing means to cut said sheets for release of sealed units. therefrom; and means to operate said sealing means and cutting means in sequence to seal a unit, and release theunit through said opening.

7. A combination as set forth in claim 6 in which said lower sealing means is ring-shaped and said lower cutting means. is also ring-shaped concentric thereto.

8. A combination as set forth in claim 6 which includes a support on which both said upper sealing means and said upper cutting means are mounted;

9, A combination as set forth in claim 8 in which said support reciprocates toward and away from said lower sealing means and lower cutting means to seal said units and to release :the units from the two sheets through said opening.

10. A combination as set forth in claim 9 in which said lower sealing means is stationary.

11. A combination as setforth in claim 10 in which said lower cutting means reciprocates vertically for cooperation with said uppersealing means. h

12. In an apparatus of the character described for packaging units of a product, the combination of: means to move a lower continuous wrapping sheet across a feed station to a'wrapping station and to move an upper continuous sheet to the wrapping station above said lower sheet; a lower support at said wrapping station below 'the .level of said two sheets, said lower support having anopening therethrough for downward passage of scaled units; an upper support at said'wrapping station above the level of said two sheets, at least one of said supports being reciprocative relative to the other; upper and lower sealing means carried by said two supports respectively; upper and lower cutting means carried by said two supports respectively, said cutting means extending on opposite sides of said sealing means; and means to cause relative reciprocation between said two supports to seal units betweensaid two sheets and to release the sealed units from the sheets through said opening.

. 13. .A combination as set-forth in claim 12 in which the sealing means on one of said supports is positioned in advance of the cutting means on the same support to initiate the sealing operation in advance of the cutting operation.

Q 14. A combination as set forth in claim 13 in which at least one of said sealing means is resiliently mounted on the corresponding support. I

15. A combination as set forth in claim 14 in which at least one of said cutting means is resiliently mounted on the corresponding support.

16. A combination as set forth in claim 15 in which said lower support is stationary.

17. In an apparatus of the character described for packaging units of a product, the combination of: means to move a lower continuoussheet across a feed station to a wrapping station and to move an upper continuous wrapping sheet to the wrapping station above the lower sheet; upper and lower co-operating sealing means respectively above and below said two sheets at said wrapping station, said lower sealing means having a central opening for downward passage of sealed units therethrough; upper and lower eo-operating cutting means respectively above and below said two sheets at said wrapping stationys'aid cutting means extending on opposite sides of said sealing means to cut said sheets for release of seal units therefrom; a first normally open switch to control said sheet-moving means, said switch being adapted to close in response to the presence of a unit at said fee'dstation; a second normally closed switch to control said sheetmoving means, the sheetmovlng means being operatively responsive only to closmg of both said switches, said second switch being adapted to open in response tomovement of a unit to said wrapping station; and means to operate said sealing and cutting means in response to movement of a unit to said sealing station.

18. A combination as set forth in claim 17 in which said operating means responds .to movement of a unit to said wrapping station and said second switch opens in response to initial operationof said operating means.

19. In an apparatus of the character described for packaging units of a product, the combination 9f; means "s 12 5 to move 'ailower' continuous wrapping-sheet across' 'g. feed station to a wrapping station and to move an upper. continuous wrapping sheet to'the wrappingstation above the lower sheet; upper and lower co-operating sealing means respectively above and below said two sheets at said wrapping station, said lower sealing means having a central opening for downward passage of sealed units therethrough; upper and lower co-operating cutting means respectively above and below said two sheets at said wrapping station, said cutting means extending on opposite sides of said sealing means to cut said sheets for release of a sealed unit therefrom; a first normally open switch to control said sheet-moving means,- said switch being adapted to close in response to thepresence of a unit at, said feed station; a second normally closed switch to control said sheet-moving means, the sheetmoving means being operatively responsive only to closing of both said switches, said second switch being adapted to open in response to movement of a unit to said mapping station; means to actuate said sealing means and cutting means in response to movement of .a unit to said wrapping station; and means responsive to said actuating means to prevent operation of said sheet-moving means until the end of the cycle of operation of the sealing and cutting means.

20. In an apparatus of the character described for packaging units of a product,. the combination of: means to move alower continuous sheet across a feed station to a wrapping station'and to move an upper continuous sheet to the Wrapping station above the lower sheet; upper and lower co operating sealing means respectively above and below said two sheets at said wrapping station, said lower sealing means having a central opening for downward passage of scaled units therethrough;-upper and lower co-operating cutting means respectively above and below said two sheets of said wrapping station, said cutting means extending onopposite sides of said sealing means to cut said sheets for release of sealed units therefrom; a first normally open switch to control said sheetmoving means, said switch being adapted to .close in response to the presence of a unit at said feed station; a second normally closed switch to control said sheetrnoving means, the sheet-moving means being operatively responsive only to closing of bothsaid switches, said second switch being'adapted to open in response to movement of a unit to said wrapping station; means. to actuate said sealing means and cutting means in response to movement of a unit into said wrapping station; and a receiver. having an operating cyclefor movement from an upper position to. receive the sealed units from said opening toa lowerlpo'sition for dischal'g 0f the sealed units, said receiver being operatively responsive to'said actuating means. I

. 21. In an apparatus of the character'described for packaging units of a product, the combination of: electrically controlled means to move alower continuous sheetvof wrapping material longitudinally across a feed'station to a sealing station; a control circuit for energizing said movingmeans; a first normally open switch -for said circuit adapted to close in response to the presence of a unit onsaid sheet at said feed station thereby to cause movement of said lower sheet to carry the unit to said sealingstation; a second normally closed switch for said circuit adapted to open in response to movementof a unit on said sheet into said sealing station thereby to stop movement of said lower sheet with the-unit thereon at said sealing station, said second switch'being 'controlled by photoelectric means responsive to a light beam positioned to be intercepted by a unit on moving into said sealing station; means to move an upper sheet longitudinally into said sealing station over the units therein on said lower sheet; means responsive to the movement of a unit into said sealing station to seal said :two sheets together around'the unit; andmeans to'cut said sheets to release the sealed unit. I V

References Cited in the filejof this patent UNI'IED' STATES PATENTS 

